Return to Recombinant Glycoprotein Expression

Glycolipids comprise another major class of glycans. These molecules are abundant components of the cellular membrane and consist of a lipid moiety attached to monosaccharide or polysaccharide chains that extend into the extracellular space.

  • Classes of glycolipids include glyceroglycolipids, lipopolysaccharides, glycosphingolipids, and glycosylphosphatidylinositols (1).
  • Glycolipids have varied functions (2,3) some of which include:
    • Eliciting host immune responses to bacterial infections
    • Modulating cell-cell communication
    • Ensuring proper myelination of axons
  • One class glycosylphosphatidylinositol anchors (GPI) attach certain proteins to the surface of eukaryotic cells.
    • GPI anchored proteins are involved in a variety of cellular processes including cell adhesion and signal transduction.
    • GPI anchored proteins also typically possess N- and/or O-linked glycans (Fig. 1).
    • GPI anchors appear to be involved in the trafficking and surface localization of a given protein, for instance there seems to be a higher abundance of GPI-anchored proteins in lipid rafts (4).

Figure 1: Schematic representation of the main events in the synthesis of GPI-anchored proteins. Proteins (often glycoproteins) acquire a GPI anchor in the ER, a signal sequence is cleaved (at a consensus omega residue) and the GPI anchor is attached via a terminal ethanolamine phosphate to the C-termini of the acceptor protein. The glycolipid moiety can be later modified in the Golgi. The mature glycoprotein is finally localized to the plasma membrane.


  1. Bastow ER, et al. (2008) Cell Mol Life Sci. 65(3):395-413. PMID: 17965830
  2. Zajonc DM, Kronenberg M. (2009) Immunol Rev. 230(1):188-200. PMID: 19594637
  3. Stoffel W, Bosio A. (1997) Curr Opin Neurobiol. 7(5):654-61. PMID: 9384539
  4. Paulick MG, Bertozzi CR. (2008) Biochemistry. 47(27):6991-7000. PMID: 18557633